Beam charge asymmetries for deeply virtual Compton scattering off the proton

The unpolarized and polarized Beam Charge Asymmetries (BCAs) of the (e) over right arrow (+/-) p -> e(+/-) p gamma process off unpolarized hydrogen are discussed. The measurement of BCAs with the CLAS12 spectrometer at the Thomas Jefferson National Accelerator Facility, using polarized positron and electron beams at 10.6 GeV is investigated. This experimental configuration allows to measure azimuthal and t-dependences of the unpolarized and polarized BCAs over a large (x(B), Q(2)) phase space, providing a direct access to the real part of the Compton Form Factor (CFF) H. Additionally, these measurements confront the Bethe-Heitler dominance hypothesis and eventual effects beyond leading twist. The impact of potential positron beam data on the determination of CFFs is also investigated within a local fitting approach of experimental observables. Positron data are shown to strongly reduce correlations between CFFs and consequently improve significantly the determination of Re[H].

Automated summary

The study discusses the unpolarized and polarized Beam Charge Asymmetries (BCAs) of the (e) over right arrow (+/-) p -> e(+/-) p gamma process off unpolarized hydrogen, using polarized positron and electron beams with the CLAS12 spectrometer at the Thomas Jefferson National Accelerator Facility. The experimental results provide insights into the azimuthal and t-dependences of the BCAs, allowing direct access to the real part of the Compton Form Factor (CFF) H. Additionally, the impact of positron beam data on the determination of CFFs is explored, showing a significant improvement in the determination of Re[H].